1. Field of Invention
The present invention relates to a proximity sensor, especially a proximity sensor including an enclosed accommodation space, and a manufacturing method thereof.
2. Description of Related Art
Various kinds of input/control devices for electronic product have been developed such as touch screen, gravity sensor, etc. The proximity sensor is one of such input/control devices and widely used in various new devices. As one application example, the proximity sensor can be used for shutting down the screen display of a cellular phone to save power when it is detected that a user's face is close to the cellular phone, which implies that the user is talking through the cellular phone. The proximity sensor senses an action of the user or a change of the electronic product, and such information can be used by the system to generate a corresponding command.
FIG. 1 shows a prior art proximity sensor 10, wherein a transmitter unit 11 transmits a light signal L which is reflected by an object and the reflected light signal L is received by a receiver unit 12; the receiver unit 12 can determine the proximity status of the object according to the received light signal L such as by its intensity. The prior art proximity sensor 10 includes openings 13 and 14 as paths for the light signal L. However, due to miniature requirement, to reduce the size of the product, the protection structure for the sensor is simplified or even removed, so dirt can fall inside the product to interfere the sensing capability and cause misjudgment or even failure to transmit or receive signals. Therefore, it is desired to protect the transmitter unit 11 and the receiver unit 12 from dirt by a simple structure.